Periodic Table O- Level Chemistry is what I call a buffer topic in O Level Chemistry. It is a relatively easy-to-understand topic and there isn’t too much to memorize. In this chapter, students are tested on the general trends in the periodic table, Group I metals, Group VII halogens, Group 0 noble gases, and transition metals.
Most of the topics involve remembering the colours, and trends of the various elements. In terms of reactions, there are just 2 reactions. These are quite important reactions since they come up frequently in exams.
One reaction is the reaction between Group I metals with water to form group I hydroxide (also known as alkalis) and hydrogen. The other reaction is the displacement reaction of halogens.
Reaction of Group I Metals with Water
Group I metals are very reactive, and they react vigorously with water, with the reaction becoming more vigorous on going down the group.
The word equation of the reaction can be written as:
group I metal + water –> group I hydroxide + hydrogen gas
Using sodium as an example:
sodium + water –> sodium hydroxide + hydrogen gas
Displacement Reaction of Group VII halogens
In this displacement reaction, the more reactive halogen will displace the less reactive halogen from its aqueous salt solution. To compare reactivity, you have got to use the fact that reactivity of halogens decrease down the group.
The reaction between aqueous chlorine and potassium bromide solution is an example of a displacement reaction.
In this reaction, the more reactive chlorine displaces bromide from its solution to form potassium bromide and bromine.
Learn Periodic Table, Acids Bases and Salts, Qualitative Analysis, Metals, Ammonia and more O Level Chemistry topics on-demand
Want to learn the periodic table, acids, bases and salts, qualitative analysis, metals, ammonia and more? Check out our On-demand chemistry courses written based on the Singapore O Level Chemistry syllabus.
In this course, students will learn the chapters on atomic structure, chemical bonding, elements, molecules and compounds, and also the fundamentals of chemistry – writing equations, and chemical formulae. Check out this course here.
2. Acids, bases and salts, Qualitative Analysis, Metals, Periodic Table, and Ammonia
In this course, students will learn acids, bases and salts, qualitative analysis, metals, periodic table and ammonia. I also share a way of remembering the metals in the reactivity series in this course. You can get this on-demand course here.
3. Mole concept and stochiometry
Questions on mole concept and stoichiometry can be combined with any other chapter. In this course, I will go through with you step- by-step all the concepts you need to know for mole concept and stoichiometry. You can get this on-demand course here.
4. Rate of reaction (reaction kinetics) and heat of reaction (enthalpy change of reaction)
These topics involve applying concepts learnt to scenario-based questions. In our on-demand course on the rate of reaction and heat of reaction, we go through the concepts and how to apply them to questions. You can get this on-demand course here.
5. Redox reactions, electrochemistry and electric cell
Learn redox reactions, and electrolysis and electric cell n this on-demand course here. Most schools cover electrolysis last, so if you want to learn ahead of your school, check out our course here.
In O Level Chemistry, students are expected to know the properties, and reactions of alkanes, alkenes, alcohols, carboxylic acids, esters and polymers (addition and condensation polymers). We talk about them in detail in our on-demand course on O Level Organic Chemistry. You can get this on-demand course here.